Search found 1550 matches

by fredrosse
Tue Jan 01, 2019 3:47 am
Forum: Technical - Engines and Boilers
Topic: Condensing Circuit Logic
Replies: 17
Views: 560

Re: Condensing Circuit Logic

In larger power plants a common efficiency goal is to keep the condensate temperature as close as possible to the saturation temperature corresponding to the condenser pressure, be it whatever prevailing vacuum. In large sea water cooled condensers, the tube bundle may be on the order of 20ft x 20ft...
by fredrosse
Tue Dec 25, 2018 9:45 pm
Forum: Technical - Engines and Boilers
Topic: Condensing Circuit Logic
Replies: 17
Views: 560

Re: Condensing Circuit Logic

"the condenser could fill up with water, and therefore not have enough cooled area to condense the incoming steam. Someone else may have tried the set-up, and found a way round the potential problem - if indeed there is a problem." If water is not flowing into the hotwell, it must collect in the con...
by fredrosse
Wed Dec 05, 2018 4:22 am
Forum: Welcome
Topic: Gordon Cheape Compound
Replies: 61
Views: 4290

Re: Gordon Cheape Compound

Drain passages can play a significant part in heat penalties, depending on the arrangement. Say you have an engine running at 125 PSIG (8.7 Barg) steam pressure, with a saturation temperature of 353F (178 C), exausting at atmospheric pressure, 0 PSIG, (0 Barg) with saturation temperature of 212F (10...
by fredrosse
Wed Nov 21, 2018 3:40 am
Forum: Sales and Trade
Topic: Buying a second hand steam boat
Replies: 3
Views: 402

Re: Buying a second hand steam boat

One of the first things to examine on the hull is the engine/boiler stringers, rotted or oil soaked softened wood? Many fiberglass hulls have a plywood transom, and many of these need a complete rebuild. As far as the steam plant goes, getting metal wall thickness on the VFT shell is necessary. Ultr...
by fredrosse
Sun Nov 18, 2018 7:30 am
Forum: Sales and Trade
Topic: Source of Pipe Elbows
Replies: 9
Views: 558

Re: Source of Pipe Elbows

Trolling on ebay can often serve as a source of low priced fittings of all sorts. The problem is that you may spend some lengthy time to find what you want. Often a class of items will go for very low prices, and then some valuable items get enough attention that they grow in prices. A good example ...
by fredrosse
Tue Nov 13, 2018 10:12 pm
Forum: Sales and Trade
Topic: Source of Pipe Elbows
Replies: 9
Views: 558

Re: Source of Pipe Elbows

Bronze-silver braze (or sil-brazed) fittings are made of ASTM B-61 or B-62 bronze and are constructed with a pipe-sized end socket with a precision groove for silver ring insert. This permits joining without additional silver solder. The absence of threads means that there is no reduction of strengt...
by fredrosse
Mon Oct 29, 2018 11:09 am
Forum: Technical - non Engines and Boilers
Topic: Cutlass Bearing V Bronze Outer Bearing ?
Replies: 10
Views: 793

Re: Cutlass Bearing V Bronze Outer Bearing ?

With the relatively low power of our steam launches, I think the need for water circulation to cool the bearing is not necessary. Water lubrication yes, but that will happen as long as at least one end of the bearing is submerged. Bearing clearance of 0.001 inch per inch of shaft diameter is the sta...
by fredrosse
Sun Oct 28, 2018 4:12 pm
Forum: Technical - non Engines and Boilers
Topic: Cutlass Bearing V Bronze Outer Bearing ?
Replies: 10
Views: 793

Re: Cutlass Bearing V Bronze Outer Bearing ?

I have an external strut on the boat, fairly far from the hull proper. A metal strut, 2 inch x 1/4 inch flat bar in a "V" shape holds the shaft bearing about 10 inches away from the hull. Turning a 14 x 17 three blade propeller. The bearing has a self aligning feature, and uses no collars or set scr...
by fredrosse
Sat Oct 27, 2018 1:51 am
Forum: Technical - non Engines and Boilers
Topic: Cutlass Bearing V Bronze Outer Bearing ?
Replies: 10
Views: 793

Re: Cutlass Bearing V Bronze Outer Bearing ?

The prop shaft on my electric boat, one inch diameter, is supported by an external strut, and it uses an UHMW food grade bearing (Ultra High Molecular Weight). Water lubrication, in service since 2004 with no problems.
by fredrosse
Fri Oct 19, 2018 2:37 pm
Forum: Technical - non Engines and Boilers
Topic: Prop shaft diameter ?
Replies: 9
Views: 391

Re: Prop shaft diameter ?

A 3/4 inch shaft, common steel, or stainless steel, or bronze will be perfectly adequate. For launch type of a couple horsepower a smaller shaft is probably adequate (although the launch I am currently building is 15 horsepower, and 14 feet long, that will have a 1 inch diameter steel shaft) and the...